Quick coupler with front pin safety lock system

ABSTRACT

Quick coupler with front pin safety lock system including body, front pin lock configured to rotate pivotally to lock in a pin, slide ratchet configured to move forward-backward to force the front pin lock to rotate, actuator including a cylinder and a piston rod which moves in the cylinder, rear lock connected to the piston rod, links configured to connect the rear lock and the slide ratchet and casing configured to house a part of the links and a part of the slide ratchet, is provided. It can work even when power is cut off and emergency front pin release can be performed.

TECHNICAL FIELD

The present invention is related to a safety pin lock system for quickcoupler used in construction equipment.

BACKGROUND ART

In the conventional technology of excavators, quick coupler is mountedat the end of arm and grapples an attachment. It has a hook on frontside and hydraulic actuating wedges on rear side. When the rear sidewedge is not engaged properly, the quick coupler can drop the attachmentand it is very dangerous. By locking the front pin when the rear wedgeis extended, dropping an attachment accident can be prevented.

US Pat. Pub. No. 2014/0294497 A1 discloses a quick coupler for holdingan implement which includes a frame having first and second plates. Thequick coupler includes a locking system adapted to lock the implement inthe first and second plates. The locking system includes securing latchmember and hydraulic actuator connected to the latch member which isconfigured to move along a guide between the first and second plates.The locking system also includes a set of grooves provided on thesecuring latch member and a guide. The set of grooves are adapted tolock the securing latch member in a latched position. However, in caseof power-off, the quick coupler stops working. Also there is noemergency release mechanism whenever something go wrong and quickrelease is needed.

This invention is to improve the shortcomings listed above.

DISCLOSURE OF INVENTION Technical Problem

The invention's objective is to provide a safety lock system for frontpin in a quick coupler, particularly used for excavators. Anotherobjective is to provide a front pin safety lock system that works evenwhen power off situation.

The objects are achieved by the features of the independent claims. Theother claims and the description disclose advantageous embodiments ofthe invention.

Solution to Problem

According to first aspect of the invention, a quick coupler apparatuscomprising body (10), pivot pin (101) attached to the body (10), lockingarm (100) pivotally attached to the pivot rod (101), actuator (120)comprising a cylinder (121) and a piston rod (122) which moves in thecylinder (121), rear wedge (130) attached to the piston rod (122) andlocking guide (110) attached to the rear wedge (130).

Moreover, the quick coupler apparatus's locking guide (110) furthercomprising release wedge (111) for moving the locking arm (100) into areleased status when inserted underneath the locking arm, and lockingstopper (112) for maintaining the locking arm (100) to a locked statuswhen positioned above the locking arm.

Also, the quick coupler apparatus's locking guide (110) is U-shaped.

Also, the quick coupler apparatus further comprising release wedge (311)and the wedge is configured to be connected to the locking guide.

Another aspect of the invention, a quick coupler apparatus comprisingbody (20), front pin lock (201) configured to rotate pivotally to lockin a pin, slide ratchet (200) configured to move forward-backward toforce the front pin lock to rotate, actuator (220) comprising a cylinder(221) and a piston rod (222) which moves in the cylinder (221), rearlock (230) connected to the piston rod, links configured to connect therear lock and the slide ratchet, and casing (240) configured to house apart of the links and a part of the slide ratchet.

Also, the quick coupler further comprising pivotal rod (241) protrudedfrom the casing.

Also, the quick coupler apparatus's links comprising a first link (211),a second link (212) and a third link (213) and the first link and thesecond link are movably joined by first link joint (215), and the secondlink and the third link are movably joined by second link joint (216).

Also, the quick coupler further comprising protruded pin (243)configured on the surface of the rear lock (230), and rear lock strokehole (214) configured within the first link.

Also, the quick coupler's second link (212) is connected with thepivotal rod (241) by rod pin (242).

Also, the quick coupler's length ratio from the first link joint topivotal rod and from the pivotal rod to the second link joint is 1:n.(wherein, n>0 and n is real number)

Also, the quick coupler further comprising first spring (250) configuredto connect the front pin lock and the body and second spring (251)placed inside of the casing.

Also, the quick coupler further comprising emergency release handler(280) for releasing the front pin quickly.

BRIEF DESCRIPTION OF DRAWINGS

The present invention together with the above-mentioned and otherobjects and advantages may best be understood from the followingdetailed description of the embodiments, but not restricted to theembodiments, wherein is shown:

FIG. 1, 2 Quick coupler with front pin safety system according to thefirst preferred embodiment of the invention from perspective view (FIG.1 ) and front the front view (FIG. 2 ) when the front pin lock is inreleased status.

FIG. 3, 4 Quick coupler with front pin safety system according to thefirst preferred embodiment of the invention from perspective view (FIG.3 ) and front the front view (FIG. 4 ) when the front pin lock is inlocked status.

FIG. 5 Detailed view of the locking guide for the first embodiment.

FIG. 6 Quick coupler with front pin safety system according to thesecond preferred embodiment of the invention from perspective view.

FIG. 7 Quick coupler with front pin safety system according to thesecond preferred embodiment of the invention from front view when thefront pin lock is in locked status.

FIG. 8 Quick coupler with front pin safety system according to thesecond preferred embodiment of the invention from front view when thefront pin lock is in released status.

FIG. 9 Quick coupler with front pin safety system according to the thirdpreferred embodiment of the invention from front view.

FIG. 10 Quick coupler with front pin safety system according to thethird preferred embodiment of the invention from front view when thefront pin lock is in released status.

FIG. 11 Quick coupler with front pin safety system according to thethird preferred embodiment of the invention from front view when thefront pin lock is in locked status.

MODE FOR THE INVENTION

The detailed structure and working mechanics for this invention will beexplained with figures.

Throughout this specification, a ‘locked status’ is a status when abucket or any attachment attached to the arm of a certain constructionequipment (i.e. an excavator) is locked to the arm so that it does notfall from the arm when the arm is raised from the ground and a ‘releasedstatus’ is a status when a bucket or any attachment attached to the armof a certain construction equipment (i.e. an excavator) can be removedfrom the arm or freely fall from the arm when the arm is raised from theground.

FIGS. 1 to 5 are describing the first embodiment.

In FIG. 1 , the front pin safety lock system comprises locking arm (100)and locking guide (110). The locking arm exercises pivotal movement bythe pivot pin (101) and the locking arm's position is determined by thelocking guide.

The actuator (120) is placed in the center of the locking guide and itexerts the power to lock or release the invention's lock system. Theactuator comprises cylinder (121) and the piston rod (122) to actuatethe movement. By the piston rod's backward movement (backward is adirection from the front pin area (191) from the rear pin area (190)),the rear wedge (130) is moving backward along with the piston rod andthe locking guide attached to the rear wedge also moves backwards andthis leads to a locked status of the lock system.

FIG. 2 shows the locked status of the lock system. The rear wedge movesbackwards until the piston rod's maximum extension range and can holdone of the pins of the bucket or other attachment. By the rear wedge'smovement the locking guide moves backwards along with the rear wedge andits locking stopper (112) moves backwards also and it positions thelocking arm in locked status.

The shape of the locking arm is such that when it is in locked status,the pin of a bucket or other attachment is prevented from sliding out byits protruding tip (100′, in dotted circle).

In FIG. 5 , the locking guide for 1st embodiment is shown in detail. Thelocking guide may comprise release wedge (111) and locking stopper(112). The locking guide's structure is U-shaped with the part of“underscore ‘_’” comprises locking stopper (112) and the two pillar-likeparts (“I”) in the ‘U’ both have release wedge (111). Each structure'susage will be explained with FIGS. 3 & 4 .

In FIG. 3 , the actuator (120)'s piston rod (121) moves into thecylinder (121) in forward direction (forward is a direction from therear pin area (190) to the front pin area (191)) so the rear wedge,which is connected to the piston rod, also moves in forward direction.In this case, the rear wedge is in released status because there isnothing that keeps the pin from slipping from the locked status.

In FIG. 4 the locking guide, which is connected to the rear wedge, alsomoves in forward direction. The release wedge (111), when locking guide(110) moves along with the piston rod and rear wedge, also moves andinserted into underneath of the locking arm. Therefore, the lockingarm's protruding tip (100′) is lowered, making the front pin area (191)open i.e. a released status. At the same time, locking stopper (112)moves deep into the locking arm, leaving end tip (100″) placed in thecenter of the locking stopper (112) so that the locking arm is inreleased status.

In FIG. 2 the actuator's cylinder pushes the piston rod out in thebackward direction the rear wedge moves backward along with the pistonrod. In this case the rear pin area becomes locked status. The lockingguide connected to the rear wedge also moves backward. The release wedgealso moves backwards and is pulled out from the underneath of thelocking arm. At the same time the also backwardly moved locking stopperis positioned in a region where the end tip (100″) is placed at the beamof the locking stopper, pushing it down. When the end tip (100″) ispushed down, the protruding tip (100′) is pivotally rotating upward tomake the front pin area closed so that the lock status is realized.

This way, the apparatus is exercising the pin locking and releasingmechanism.

FIGS. 6 to 8 are descriptions of the second embodiment.

FIG. 6 shows the overview of the second embodiment of the apparatus.

In this second embodiment, the body (30) of this apparatus comprises anactuator (320), rear wedge (330), the locking guide (310) and thelocking arm (300). The actuator may comprise a cylinder (321) and apiston rod (322). The piston rod (322) may be connected to rear wedge(330) and each of the locking guide (310) is connected to the rearwedge. Release wedge (311) is connected to the locking guide (310) bylink joint (312). The locking arm (300) is attached pivotally movable tothe body with a pivot pin (301). The release wedge (311) is shaped in away that the thickness is thin toward the rear wedge but it graduallyincreases toward the locking arm (300).

The locking arm (300) equipped with a spring (301′) at the pivot pin(301) so that the contact tip (300′) is always pushed downward by thespring (301′)'s elasticity.

FIG. 7 shows when this apparatus is in a locked status in secondembodiment. When the front and rear pins are within the range of frontpin area (391) and rear pin area (390) respectively, is attached to thebody (30) with a pivot pin (301) and it can pivotally rotate with thepivot pin (301) in the center. When cylinder (321) of the actuator (320)pushes out the piston rod (322) backwards, the rear wedge (330)connected to the piston rod (322) also moves backwards therefore placingthe rear wedge in locked status. At the same time, the locking guide,connected to the rear wedge also moves backwards. The locking armconnected to the locking guide also moves backwards. The shape of therelease wedge (311) and the spring (301′) of the locking arm make thelocking arm's contact tip to gradually move upward following the surfaceof the release wedge. While the contact tip is moving upward, theopposite tip (300″) is moving downward and by this movement the lockingarm is in locked status, locking the front pin area.

In FIG. 8 , when trying to change the attachment or the bucket, theactuator's piston rod moves into the cylinder (i.e. forward direction).By this movement, the rear wedge moves forward along with the pistonrod, rendering the rear wedge in a released status.

Also, the locking guide (310), connected to the rear wedge, moves alongwith it in forward direction and the release wedge (311) does too. Bythe shape of the release wedge and the spring (301′)'s elasticity, thelocking arm's contact tip moves down following the surface of therelease wedge. At the same time, the opposite tip moves up, renderingthe locking arm in a released status.

FIGS. 9 to 11 are descriptions for the third embodiment.

FIG. 9 shows the overview of the third embodiment of the apparatus.

Forward direction means a direction from the rear pin area (290) to thefront pin area (291) and backward direction means a direction from thefront pin area (291) to the rear pin area (290).

In this embodiment, the apparatus comprises a body (20), an actuator(220) comprising cylinder (221) and piston rod (222), rear lock (230)connected to the piston rod (222), slide ratchet (200) configured tomove front pin lock (201) that is configured to lock the front pin inthe front pin area (291), links (211, 212, 213) that connect the rearlock (230) and the slide ratchet (200).

The slide ratchet (200) is shaped so that it may push the front pin lock(201) in forward direction when the actuator is activated and the pistonrod is pushed in backward direction. In this case the front pin lock ispositioned to a released status. (because the front pin lock is open tothe forward direction) A spring (250) may be installed at the front pinlock (201) so that when no outer force is engaged, the front pin lock(201) is in locked status (i.e. the front pin lock is closed). A frontpivot pin (202) is installed so that the front pin lock (201) isrotationally configured in the body (200).

The links (211, 212, 213) are joined by link joints (215, 216)respectively. At the slide ratchet (200)'s rear pin area (290) directionend, the link (213) is connected to the link (212) with the link joint(216). A casing (240) covers part of the link (213) and the slideratchet (200) with a hold which lets the link (213) move forward andbackward directions. A pivotal rod (241) is configured at the end thecasing (240) and rod pin (242) is connecting the link (212) and thepivotal rod (241).

A spring (251) may be installed in the casing so that it touches thecasing's backward direction wall and the slide ratchet. This spring(251) may exert elastic force to keep the slide ratchet's position inplace. Another spring (250) may connect between the front pin lock (201)and an appropriate place in the body (20). The spring (250) may placethe front pin lock (201) in place, i. e. keep the front pin lock (201)closed for locked status.

FIG. 10 describes when the third embodiment's front pin lock (201) is inreleased status (open).

As the piston rod (222) moves to the backward direction, the first link(211) connected to the piston rod (222) also moves to the backwarddirection. The second link (212), rotatably fixed by the rod pin (242),rotates in counter-clockwise direction. The second link joint (216)moves in forward direction along with the third link (213).

The slide ratchet (200) moves forward direction along with the thirdlink so that the front pin lock (201) opens to be in released status.The spring (250) may keep the front pin lock (201) in contact with theslide ratchet (200).

FIG. 11 describes when the third embodiment's front pin lock (201) is inlocked status (close).

As the piston rod (222) moves to the backward direction, the first link(211) connected to the piston rod (222) also moves to the backwarddirection. The second link (212), rotatably fixed by the rod pin (242),rotates in clockwise direction. The second link joint (216) moves inbackward direction along with the third link (213).

The slide ratchet (200) moves backward direction along with the thirdlink (213) so that the front pin lock (201) closes to be in lockedstatus. The spring (250) may keep the front pin lock (201) in contactwith the slide ratchet (200).

The rear lock stroke hole (214) can be configured in the first link(211). When this stroke hole is in the first link, the first link isconnected to the rear lock (230) with protruded pin(s) (243).

The protruded pin (243) is on the surface of the rear lock (230) and itis positioned inside the stroke hole (214) and when the rear lock movesthe protruded pin also moves with the rear lock.

This stroke hole (214) and the protruded pin (243) can provide a slackin the movement of the front pin lock (201).

When the piston rod (222) moves forward or backward, the rear lock (230)moves at the same time. However, the links (e.g. the first link (211))do not move until the protruded pin (243) meets the end of the hole.Until the encounter, the links do not move.

This slight ‘lack of movement’ gives some stroke slack to this apparatusbecause if all the components in this apparatus move with the piston rodimmediately, there can be some shortcomings due to the extra-sensitivityfrom it.

The second link (212) has a fixed rotation center in the middle (rodpin, 242). The rod pin divides the second link in a certain way. Formaximum efficiency and prolonging parts life, the length ration can bevaried.

The length ratio from the first link joint (215) to the pin rod (242) tofrom the pin rod (242) to the second link joint (216) is 1:n, wherein nis a positive real number.

However, if the ratio is too big (for example, n is smaller than 1) thefirst link (211) should move long enough to get the slide ratchet (200)move enough so that the front pin lock (201) can open (i.e. releasedstatus). This long movement sometimes can lead into malfunction.

On the contrary, if the ratio is too small (for example, n is muchbigger than 1) the first link (211) may move just a little to get theslide ratchet move for released status. But, it would require so muchforce to move the slide ratchet when front pin is attached so the links,especially the second link and then the first link are under too heavypressure every time they move. This can lead into snapping anddangerous.

So, good length ratio for maximizing the efficiency and prolonging partlife is important.

For better changing the ratio for supporting each work'scharacteristics, the second link (212) has multiple puncture holes init.

This embodiment's front lock mechanism is mechanical not electrical orelectronic, so the front lock system works when even power cut off(i.e., no hydraulic power).

For emergency, the emergency release handler (280) may be manipulated sothat the second link joint (216) ejects from its position. In this case,the spring (251) exerts its force to the slide ratchet (200) to releasethe front pin in spite of the spring (250).

Explanation of Reference Numbers

-   -   10, 20, 30: Body    -   100, 300: Locking arm    -   100′: Protruding tip    -   100″: End tip    -   101, 301: Pivot pin    -   101′, 301′: Spring    -   110, 310: Locking guide    -   111,311: Release wedge    -   112: Locking stopper    -   120, 220,320: Actuator    -   121, 221, 321: Cylinder    -   122,222, 322: Piston rod    -   130, 330: Rear wedge    -   190, 290, 390: Rear pin area    -   191, 291, 391: Front pin area    -   200: Slide ratchet    -   201: Front pin lock    -   202: Front pivot pin    -   250, 251: Spring    -   211, 212, 213: Link    -   214: Rear lock stroke hole    -   215, 216, 312: Link joint    -   230: Rear lock    -   240: Casing    -   241: Pivotal rod    -   242: Rod pin    -   280: Emergency release handle    -   300′: Contact tip    -   300″: Opposite tip

1. A quick coupler apparatus comprising, a body; a front pin lockconfigured to rotate pivotally to lock in a pin; a slide ratchetconfigured to move forward-backward to force the front pin lock torotate; an actuator comprising a cylinder and a piston rod which movesin the cylinder; a rear lock connected to the piston rod; a plurality oflinks configured to connect the rear lock and the slide ratchet; and acasing configured to house a part of the links and a part of the slideratchet.
 2. The quick coupler apparatus of claim 1, further comprising,a pivotal rod protruded from the casing.
 3. The quick coupler apparatusof claim 2, wherein the links comprising a first link, a second link anda third link and the first link and the second link are movably joinedby first link joint, and the second link and the third link are movablyjoined by second link joint.
 4. The quick coupler apparatus of claim 3,further comprising, a protruded pin configured on the surface of therear lock; and a rear lock stroke hole configured within the first link.5. The quick coupler apparatus of claim 3, wherein the second link isconnected with the pivotal rod by a rod pin.
 6. The quick couplerapparatus of claim 3, wherein length ratio from the first link joint topivotal rod and from the pivotal rod to the second link joint is 1:n,wherein, n>0 and wherein n is real number.
 7. The quick couplerapparatus of claim 1, further comprising, a first spring configured toconnect the front pin lock and the body; a second spring placed insideof the casing.
 8. The quick coupler apparatus of claim 1 any one of theclaims above, further comprising, an emergency release handler forreleasing a front pin quickly.
 9. A quick coupler apparatus comprising,a body; a pivot pin attached to the body; a locking arm pivotallyattached to the pivot rod; an actuator comprising a cylinder and apiston rod which moves in the cylinder; a rear wedge attached to thepiston rod; and a locking guide attached to the rear wedge.
 10. Thequick coupler apparatus of claim 9, the locking guide furthercomprising, a release wedge for moving the locking arm into a releasedstatus when inserted underneath the locking arm, and a locking stopperfor maintaining the locking arm to a locked status when positioned abovethe locking arm.
 11. The quick coupler apparatus of claim 10, whereinthe locking guide is U-shaped.
 12. The quick coupler apparatus of claim9, the quick coupler further comprising, a release wedge is configuredto be connected to the locking guide.